Are you weight training? Doing cardio? Both? I assume if you have a personal trainer you are weight training. Hooray for the inches lost. That should be your bigest motivator at first. I know they say muscle weighs more than fat. Really 1 pound of fat weighs the same as 1 pound of muscle. I believe however that 1 pound of muscle takes up less space than 1 pound of fat. So if you are losing inches, you may be losing a good amount of fat and building up muscle. If you are weight training, I bet you are retaining water in your muscles. They may retain that water until they get used to your routine. It took me about 4 weeks after starting a weight training program to see a difference on the scale. I even gained some weight, but now it is coming off better. There is just something so mentally rewarding about seeing the numbers on the scale drop though, yes?
I agree with cjohnson in that you might not be eating enough. How is your sodium intake?
Keep up your spirits. It's a tough battle always. Just don't give up.
Goal weight 117 by 2014